Related papers: Efficient decoupling of a non-linear qubit mode from its environment

Efficient decoupling of a non-linear qubit mode from its environment

URL: http://arxiv.org/abs/2312.16988v1
Date: Thu, 28 Dec 2023 12:16:29 GMT
Title: Efficient decoupling of a non-linear qubit mode from its environment
Authors: Frederik Pfeiffer, Max Werninghaus, Christian Schweizer, Niklas Bruckmoser, Leon Koch, Niklas J. Glaser, Gerhard Huber, David Bunch, Franz X. Haslbeck, M. Knudsen, Gleb Krylov, Klaus Liegener, Achim Marx, Lea Richard, Jo\~ao H. Romeiro, Federico Roy, Johannes Schirk, Christian Schneider, Malay Singh, Lasse S\"odergren, Ivan Tsitsilin, Florian Wallner, Carlos A. Riofr\'io, Stefan Filipp
Abstract summary: We make use of the design flexibility of superconducting quantum circuits to form a multi-mode element with symmetry-protected modes. The proposed circuit consists of three superconducting islands coupled to a central island via Josephson junctions. We show that the coherence of the qubit is not limited by photon-induced dephasing when detuning the mediator mode from the readout resonator.
Score: 0.9533143628888118
License: http://creativecommons.org/licenses/by-sa/4.0/
Abstract: To control and measure the state of a quantum system it must necessarily be coupled to external degrees of freedom. This inevitably leads to spontaneous emission via the Purcell effect, photon-induced dephasing from measurement back-action, and errors caused by unwanted interactions with nearby quantum systems. To tackle this fundamental challenge, we make use of the design flexibility of superconducting quantum circuits to form a multi-mode element -- an artificial molecule -- with symmetry-protected modes. The proposed circuit consists of three superconducting islands coupled to a central island via Josephson junctions. It exhibits two essential non-linear modes, one of which is flux-insensitive and used as the protected qubit mode. The second mode is flux-tunable and serves via a cross-Kerr type coupling as a mediator to control the dispersive coupling of the qubit mode to the readout resonator. We demonstrate the Purcell protection of the qubit mode by measuring relaxation times that are independent of the mediated dispersive coupling. We show that the coherence of the qubit is not limited by photon-induced dephasing when detuning the mediator mode from the readout resonator and thereby reducing the dispersive coupling. The resulting highly protected qubit with tunable interactions may serve as a basic building block of a scalable quantum processor architecture, in which qubit decoherence is strongly suppressed.

Related papers

The quantromon: A qubit-resonator system with orthogonal qubit and readout modes [2.516358999617711]
We introduce a two-mode circuit, nicknamed quantromon, with two modes implementing a qubit and a resonator. Experiments implemented in a hybrid 2D-3D cQED architecture demonstrate some unique features of the quantromon.
arXiv Detail & Related papers (2025-01-29T06:41:29Z)
Dissipating quartets of excitations in a superconducting circuit [0.0]
In this work, we leverage a genuine six-wave mixing process enabled by a near Kerr-free Josephson element to enforce dissipation of quartets of excitations in a superconducting resonator. We show an order of magnitude enhancement of the state decay rate while only marginally impacting the relaxation and coherence of lower energy states. These results pave the way toward the dynamical stabilization of four-component Schr"odinger cat qubits and even more complex bosonic qubits.
arXiv Detail & Related papers (2025-01-10T13:40:51Z)
Quantum microwaves: stabilizing squeezed light by phase locking [0.0]
Josephson junctions coupled to microwave cavities are a versatile and simple source for microwaves with quantum characteristics. A drawback of this method is that it suffers from bias voltage noise, which disturbs the phase of the junction. We describe how adding a small ac reference signal either to the dc-bias or directly into the cavity can stabilize the system and counteract the sensitivity to noise.
arXiv Detail & Related papers (2024-12-02T13:51:26Z)
Parity-dependent unidirectional and chiral photon transfer in reversed-dissipation cavity optomechanics [11.712867508048555]
We show broadband nonreciprocal photon transmission in the emphreversed-dissipation regime. In the reversed-dissipation regime, the nonreciprocal bandwidth is no longer limited by the mechanical mode linewidth. We find that the direction of the unidirectional and chiral energy transfer could be reversed by changing the emphparity of the Eps.
arXiv Detail & Related papers (2022-12-22T23:57:00Z)
Experimental realization of deterministic and selective photon addition in a bosonic mode assisted by an ancillary qubit [50.591267188664666]
Bosonic quantum error correcting codes are primarily designed to protect against single-photon loss. Error correction requires a recovery operation that maps the error states -- which have opposite parity -- back onto the code states. Here, we realize a collection of photon-number-selective, simultaneous photon addition operations on a bosonic mode.
arXiv Detail & Related papers (2022-12-22T23:32:21Z)
Resolving Fock states near the Kerr-free point of a superconducting resonator [51.03394077656548]
We have designed a tunable nonlinear resonator terminated by a SNAIL (Superconducting Asymmetric Inductive eLement) We have excited photons near this Kerr-free point and characterized the device using a transmon qubit.
arXiv Detail & Related papers (2022-10-18T09:55:58Z)
Nonreciprocal devices based on voltage-tunable junctions [48.7576911714538]
We propose to couple the flux degree of freedom of one mode with the charge degree of freedom of a second mode in a hybrid superconducting-semiconducting architecture. Nonreciprocity can arise in this architecture in the presence of external static magnetic fields alone.
arXiv Detail & Related papers (2022-09-13T17:49:19Z)
Accelerated Gaussian quantum state transfer between two remote mechanical resonators [0.0]
We devise a fast and reliable evolution path between two remote mechanical modes in separate optomechanical systems. A quantum state transfer between the two nodes is conceived by engineering their coupling to an intermediate fiber optical channel. Results show that while the adiabatic passage protocol is very sensitive to the decoherence, the shortcut to adiabaticity provides a robust and fast quantum state transfer.
arXiv Detail & Related papers (2022-05-17T06:41:26Z)
Noise-resilient Edge Modes on a Chain of Superconducting Qubits [103.93329374521808]
Inherent symmetry of a quantum system may protect its otherwise fragile states. We implement the one-dimensional kicked Ising model which exhibits non-local Majorana edge modes (MEMs) with $mathbbZ$ parity symmetry. MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism.
arXiv Detail & Related papers (2022-04-24T22:34:15Z)
Superconducting coupler with exponentially large on-off ratio [68.8204255655161]
Tunable two-qubit couplers offer an avenue to mitigate errors in multiqubit superconducting quantum processors. Most couplers operate in a narrow frequency band and target specific couplings, such as the spurious $ZZ$ interaction. We introduce a superconducting coupler that alleviates these limitations by suppressing all two-qubit interactions with an exponentially large on-off ratio.
arXiv Detail & Related papers (2021-07-21T03:03:13Z)
A low-loss ferrite circulator as a tunable chiral quantum system [108.66477491099887]
We demonstrate a low-loss waveguide circulator constructed with single-crystalline yttrium iron garnet (YIG) in a 3D cavity. We show the coherent coupling of its chiral internal modes with integrated superconducting niobium cavities. We also probe experimentally the effective non-Hermitian dynamics of this system and its effective non-reciprocal eigenmodes.
arXiv Detail & Related papers (2021-06-21T17:34:02Z)

This list is automatically generated from the titles and abstracts of the papers in this site.